1. Field of the Invention
This invention relates to X-ray apparatus having a telescopic column and to a method of constructing such a column.
2. Prior Art
X-ray apparatus provided with telescoping supports of various types are well known. While telescoping supports are desirable due to their inherent strength and compact construction, most known telescopic supports present a number of problems when used in conjunction with X-ray equipment.
The forces which X-ray apparatus imposes on telescopic supports are both large in magnitude and variable in direction depending upon the positioning of the apparatus. The X-ray tube housing, support, and associated counterweight mechanisms are inherently heavy, and impose lateral forces on the telescoping sections which vary in accordance with the position of the apparatus. The X-ray tube power cables which connect with the tube housing are also heavy, bulky, and serve to impose forces on the column that vary with position.
One problem with typical telescopic columns is that the guide structure for telescoped sections is not constructed to minimize accumulated play in a radial direction of the telescopic sections, and therefore they are less rigid than desired, especially when fully extended. A further problem is that it is difficult and expensive to construct telescoping parts with accurate fits so that small tolerances can assure maximum rigidity, yet provide smooth operation. Typically, the telescopic construction does not lend itself to readily fabricating columns of different lengths, without changing the tooling, setup fixtures, etc. This is especially true where the telescopic sections include specialized end formations that prevent their being simply cut off to provide shorter sections. Hence, with such sections, the length of a column to be constructed is limited by the range of lengths and diameters of sections available.